Transfer tubes often are utilized in aircraft engines to transmit engine air having one temperature and pressure from one chamber to another chamber physically removed from the one chamber. The transfer tube may span a third chamber having a different air temperature and pressure than the air temperature and pressure in the transfer tube, and the air in the transfer tube should be isolated from the air in the third chamber. Generally, the objective is to move the air from the first chamber into the second chamber without leaking the air into the third chamber.
To achieve this objective, the transfer tube typically is placed into and maintained in intimate contact with interface seats at the first and second chamber. The interface contact, however, has to avoid wear from differential motion which could cause leakage and rattle induced vibratory distress. The interface requirements of minimal leakage and vibratory integrity are in conflict with the requirements of low interface wear and of allowing differential motion between the transfer tube ends.
Satisfying the interface requirements often is achieved by off-optimizing each individual requirement. These compromises often result in less than desired transfer tube mission life and sealing performance. It would be desirable to provide a transfer tube connection which minimizes leakage and wear yet provides maximum differential motion and vibratory integrity.